The present invention relates to a printing-material conveyor device for printing units of printing machines, in particular tin-plate printing machines, in which the printing-material conveyor device is arranged behind a (first) printing unit, has a displaceable section for access to the first printing unit, has a delivery as well as a transport device, and feeds the printing material, preferably tin plates, to a further processing place, in particular a further (second) printing unit, the transport device having at least one endless conveyor with push members for the printing material.
A printing-material conveyor device of the aforementioned type is known and serves to feed printing material leaving the printing unit of the printing machine to a further processing point, in particular another printing unit of a multi-color printing machine. The printing-material conveyor device has an endless belt conveyor consisting of a plurality of belts extending parallel to and spaced from each other, it conveying the printing material out of the printing unit housing. Adjoining the said endless belt conveyor there is another, similarly developed endless belt conveyor which conveys the printing material to a higher level where it is transferred to a transport device which also has endless courses. These endless courses are aligned horizontally and lead to the adjoining further processing place, in particular to a further printing unit. At least one of the endless courses of the transport device is developed as an endless conveyor provided with push members. It preferably has two chains rotating parallel to and spaced from each other which have shark-fin-like push members for engagement behind the corresponding rear edge of the printing material. Printing material, for instance a tin plate, which leaves the (first) printing unit is thus fed by means of the two endless conveyors arranged one behind the other which form a so-called delivery, to the horizontally extending course of the transport device, in which connection the endless conveyors which have shark-fin-like push members of the endless conveyor having chains engage behind the rear edge of the tin plate and in this way feed the printing material to the following printing unit. During the course of this feeding process, the shark-fin-like members are overtaken by push rollers of an endless course of the transport device which take over the rear edge of the tin plate and feed the front edge of the plate to the feed guide stops of the printing cylinder of the following printing unit with somewhat increased speed. The push rollers, which are under spring tension, produce an accurate position of the front edge of the tin plate against the feed guide stops and after the application of the tin plate move down corresponding to the deflection region of the corresponding endless course. The transfer described of the plates from the shark-fin-like push members onto the push rollers is necessary in order to prevent the relatively far upward extending push members from damaging the rear edge of the plate upon the moving down. The endless belt conveyor of the known printing-material conveyor device leading to the transport device is preferably developed in two parts, that is it has a swing shaft between its two ends in such a manner that it can assume a V-shaped position--as seen from the operator's side--with the result that the end which in operating position faces the printing unit on the delivery side extends obliquely or vertically upwards so as to result in a position of release, i.e. a "lane" is formed in the printing-material conveyor path which permits access to the printing unit. Since, on the one hand, the endless conveyor which permits such access has a given structural length which is determined by the design and, on the other hand, the following transport device also cannot have less than a given structural length which determines in part the largest possible format of the printing material, this leads to a relatively large distance between the individual printing units of a multi-color printing machine. It there is concerned, for instance, a four-color printing machine to which tin plates are fed by means of a delivery from a stack and which is followed by a varnishing machine, there then results a total structural length of about 30 meters; in other words the known structural shape requires a correspondingly large space for installation.